Process and apparatus for producing two-colored or multicolored films, and dashboard films or dashboards produced therefrom for motor vehicles

ABSTRACT

Process and device for producing two-colored or multicolored switchboard films, dashboard films or dashboards for motor vehicles produced therefrom using at least one backing film or backing layer, at least one upper film or upper layer which is arranged thereon and contains dyes and/or color pigments. The polymer melts for these films or layers come from two or more extruders and are supplied first to an adapter or a black box having at least one opening or a gap for the backing film or layer and at least one further opening for the upper film or upper layer. According to the invention, an adapter or a black box is used in which a wedge-shaped projection or a projection of triangular cross section is arranged. At least two different-colored polymer compositions in melt form, having identical viscosity or virtually identical viscosity (difference in MFI at 230° C./2.16 kg of 0 to 0.5 g/10 min), are employed for the upper film or upper layer, and are first of all separated or partially separated by the wedge-shaped projection or projection of triangular cross section in the adapter or in the black box but then, after having passed through the adapter or the black box, are guided alongside one another, the different-colored melts of the upper films combining with the melt layer of the lower film or lower layer prior to exiting the extruder die.

This application is a division of application Ser. No. 08/704,006, filedAug. 22, 1996, pending.

BACKGROUND OF THE INVENTION

The present invention relates to a process and an apparatus forproducing two-colored or multicolored switchboard films, dashboard filmsor dashboards produced therefrom for motor vehicles. The films have atleast one backing film or backing layer, at least one upper film orupper layer which is arranged thereon and contains dyes and/or colorpigments, and, if desired, further layers or films. The polymer meltsfor these films or layers come from two or more extruders, and aresupplied first to an adapter or a black box having at least one openingor a gap for the backing film or layer and at least one further openingfor the upper film or upper layer.

By means of the present invention it is possible to produce switchboardfilms, dashboard films or dashboards produced therefrom, comprising atleast one backing layer or backing film, at least one upper film orupper layer which is arranged thereon and contains dyes and/or colorpigments, and, if desired, further layers or films. The upper film orupper layer comprises at least two differently colored or pigmentedzones or sections which extend parallel or approximately parallel andwhich are rectangular or parallelogrammic in plan view, and thedifferent-colored upper film(s) or upper layer(s) are produced as acomposite film together with at least one lower film or lower layer bycoextrusion or polyextrusion.

EP-A-0 475 004 discloses a process for producing multicolored slushskins (moldings) with different color regions, especially dashboards formotor vehicles and the like. In this process slush material (powder orpaste) is introduced into a mold which determines the shape of the slushskin and can be heated to a molding temperature. The slush material isdistributed and deposited on the heated mold surface by rotation of themold, then is sintered and gelled, and finally the slush skin is removedfrom the mold after the latter has cooled. Corresponding different slushmaterials for the respective colors are used for the different colorareas of the slush skin. In accordance with this process, in therotational sintering mold the colored polymer is introduced in specificsteps and sections of the rotational mold, it being possible tosubdivide these by means of fillets, and then the powder trough orpowder mold is rotated. This process is limited to the slush process orpowder rotational sintering process and cannot be carried out as anextrusion process. Because of necessary restrictions on the polymers,virtually only PVC can be employed.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an improved processand apparatus for producing two-colored or multicolored films suitablefor vehicle dashboards. A further object of the invention is to providetwo-colored or multicolored switchboard films or dashboard films whichcan be produced in whole or in part using, inter alia, extruders and forwhich it is possible to employ not only PVC, but, in particular,thermoplastic and/or thermoelastic synthetic resins.

In accomplishing the foregoing objects, there has been providedaccording to the present invention, a process for producing two-coloredor multicolored films, suitable for producing dashboard components,having at least one backing layer, at least one upper layer which isarranged thereon and contains a dye and/or color pigment. The processcomprises:

continuously supplying polymer melt for each layer, from a separate oneof two or more extruders to an adapter unit having at least one openingfor the backing layer, at least one further opening for the upper layer,and a projection of generally triangular cross section arranged adjacentthe further openings;

passing at least two differently-colored polymer compositions in meltform, having at least nearly identical viscosity through the adaptor tomake up the upper layer, and first at least partially separating thesepolymer compositions by the projection of triangular cross section inthe adapter; and

after passing through the adapter, guiding these polymer compositionscontiguously alongside one another in an extruder die along with themelt of the lower layer to form a coextruded film wherein the upperlayer is a combination of the differently-colored polymer compositions.

According to another aspect of the present invention there has beenprovided an apparatus for the production of two-colored or multicoloredfilms, suitable for producing dashboards. The apparatus comprises:

at least two extruders;

at least one adapter having at least three openings for the receiving asupply of polymer melt from a respective extruder or a backing layer,and, downstream of the adapter, an extruder slot die, wherein at leasttwo of the openings made in the adapter are arranged on either sideadjacent to a projection of triangular cross section, and at least onefurther opening is an inlet opening for at least one backing layer andis disposed on the opposite side of the projection from the openingswhich are arranged on the two sides of the projection.

According to still another aspect of the present invention there hasbeen provided a dashboard film which comprises: at least one backinglayer, at least one upper layer which is arranged on the backing layerand contains dyes and/or color pigments, wherein the upper layercomprises at least two zones which extend at least approximatelyparallel, are rectangular or parallelogrammic in plan view and arepigmented or colored differently, and the differently-colored upperlayer zones are produced as a composite film by coextrusion togetherwith at least one lower layer.

Further objects, features and advantages of the present invention willbecome apparent from the detailed description of preferred embodimentswhich follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sideview of the apparatus according to the presentinvention; and

FIG. 2 is a detailed schematic front view of the adapter of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In arriving at the present invention, numerous experiments were carriedout. For example, a composite film was provided in certain areas with adifferent-colored coating to give one region with a colored coating andthe other region with a different color, i.e., that of the upper film.This embodiment has the disadvantage that the coating protrudes from thefilm in terms of thickness and, in addition, there is an increased riskof delamination.

In one experiment, fillets were introduced into the extruder slot die.When full-length fillets were produced and different-colored plasticswere introduced into the respective fillet areas, flaws were noted atthe transition line, i.e., in the region of transition of the colors(regions or lines where the different-colored plastic films or plasticlayers meet). When, alternatively, the fillets in shorter form were heldwithin the extruder slot die, disruptive zones of mixed color occurred.

In accordance with the invention it has been found that theabove-enumerated objectives are accomplished by a novel process and adevice for producing two-colored or multicolored switchboard films,dashboard films or dashboards produced therefrom using at least onebacking film or backing layer, at least one upper film or upper layerwhich is arranged thereon and contains dyes and/or color pigments. Thepolymer melts for these films or layers come from two or more extrudersand are supplied first to an adapter or a black box having at least oneopening or a gap for the backing film or layer and at least one furtheropening for the upper film or upper layer. According to the invention,an adapter or a black box is used in which a wedge-shaped projection ora projection of triangular cross section is arranged. In this case, atleast two different-colored plastics in melt form, having preferablyidentical viscosity or virtually identical viscosity (difference in MFIat 230° C./2.16 kg of 0 to 0.5 g/10 min) are employed for the upper filmor upper layer, and are first of all separated or partially separated bythe wedge-shaped projection or projection of triangular cross section inthe adapter or in the black box but then, after having passed throughthe adapter or the black box, are guided alongside one another withoutthe use of a fillet to separate the two melts. The different-coloredmelts of the upper films combine with the melt layer of the lower filmor lower layer prior to exiting the extruder die.

According to a preferred embodiment of the novel process, the melts forthe upper film or upper layer, differing in their dye content and/orcolor pigment content, are led in or guided into the adapter (or theblack box) from in each case at least one opening, initially separatedby the wedge-shaped projection or projection of triangular cross sectionin the adapter. The respective openings are disposed on either sideadjacent to the projection. Alternately, or in addition, the melt(s) forthe lower film(s) is led in or guided in from at least one inlet openingor from a gap which is arranged below or above the opening(s) for theupper layer and below or above the wedge-shaped projection, but in sucha way that the tip of the wedge-shaped projection points to the gap orthe gaps for the lower film. The melt mass streams of thedifferent-colored surface regions (of the upper film) are in this waycombined with the melt mass streams of the lower film(s).

The ready-formed or melt-form film emerging from the extruder slot dieis already characterized by a modified appearance as a result of anappropriate selection of the dyes and/or of the concentrations of dye orcolor pigment and/or by means of different-colored fillers, in such away that it has in each case a lighter and darker surface region.Alternatively, or additionally, the composite film emerging from theextruder is subsequently subjected to further processing or treatment.

According to another preferred embodiment, the ready-formed or melt-formfilms emerging from the extruder slot die are divided, by means of theappropriate control of the fed melt streams of the upper film or surfacelayers, into a relatively wide surface region which is relatively lightor is colored with light dyes and/or color pigments (fittings region,region A) and a relatively small surface region (region adjacent to thewindshield, region F) which extends parallel or approximately parallelthereto and is relatively dark or is provided with relatively dark dyesand/or color pigments, so that the upper film or surface layer has thesedifferent-colored regions.

This embodiment is of importance in asmuchas the increasingly slopingwindshields of automobiles (lower drag coefficient) present the dangerof light-colored dashboards being reflected in the glass and adverselyaffecting the driver's sight. On the other hand, light-colored interiorsin the car are often required. In order to avoid the reflection in thewindshield, but despite this to enable a light-colored interior, thedashboard is divided up in accordance with a preferred embodiment suchthat one film region (of the upper film or the upper layer) or one halfis dark, for example, dark gray, and the other half or the other filmregion is light, for example, light gray (in the direction of theproduction sequence). The darker region of the film constitutes what issubsequently the region of the dashboard adjacent the front windshield.

According to a particularly preferred embodiment, the pressure of theindividual plastic or extrudate mass streams (measured prior to entryinto the adapter), preferably the pressure of the mass streams for theupper film, is kept constant or virtually constant. According to oneembodiment, the pressure of the mass streams for the upper film is alsopreferably constant in the adapter as well.

By means of the form and position of the wedge-shaped projection orprojection of triangular cross section and/or of the melt mass streamswhich enter into the adapter or the black box, which streams areinfluenced and/or controlled by the capacity of the connected extruderand/or by the inlet opening (or feed lines), the width of the regions Aand F for the upper film can be modified.

According to a preferred embodiment, the same synthetic resins are usedfor the upper film regions or surface layer regions A and F, butdifferent dyes and/or color pigments or different concentrations of dyeand/or color pigment are employed. By means of this embodiment it ispossible to establish a difference in viscosity of zero or virtuallyzero for the polymers and for the colored melt mass as well.

According to a preferred embodiment, the tip of the wedge-shapedprojection or projection of triangular cross section arranged above thegaps or the opening for the melt of the lower film(s) or lower layer(s)is directed toward the gap or the melt opening for the lower film, thetip being fixed or adjusted relative to the darker-colored region F sothat a relatively wide surface layer region A and a relatively smallsurface region F (dark-colored) are established in the emerging film.The wedge-shaped projection is arranged together with the gaps oropenings for the melts on an element, molding or insert, preferably on adisk, and the molding, element or insert is inserted into the adapter orinto the black box prior to the production process and is fastenedtherein or substituted therein. According to a preferred embodiment, thewedge-shaped projection is configured in the manner of a fillet and isarranged in the adapter or on the insert.

The insert component or the insert or the element is constructed suchthat the two different-colored extrudates (melts) do not contact oneanother in the black box and can therefore not mix. The mass streams areseparated by means of a fillet or the wedge-shaped projection, whichaccording to one embodiment is configured in the manner of a fillet.

According to one embodiment, the coextrudate is extruded onto or laidonto the melt of the backing film which comes from the main extruder.The mass flows to the die without becoming mixed and is distributeduniformly over the width of the die. Preferably, however, the melt ofthe lower film is arranged above the inherently colored or artificiallycolored melts of the upper film.

From the die there emerges a melt which possesses at least one backingfilm or backing layer, carrying, for example, a dark gray and light grayupper film. The proportion in terms of width between light gray and darkgray is determined by the position of the wedge-shaped projection orfillet in the black box, which position is variable.

Owing to the fact that in one embodiment the different-colored meltsconstitute the same product (formulation), which differs only in termsof coloring, the difference in viscosity which is established accordingthis preferred embodiment is zero or virtually zero.

The hot extrudate webs or melt-form plastic webs produced by the processare subsequently supplied to a polishing-roll stack comprising at leasttwo, preferably at least three polishing rolls. The polishing roll whichcomes into contact with the two-colored or multicolored plasticextrudate of the upper film is at a heat setting which is more than 30°C., preferably more than 45° C., hotter than that of the polishing rollwhich comes into contact with the lower film(s).

In this context, polishing rolls or polishing-roll stacks with orwithout an embossing structure are used. The polishing rolls are cooledor thermostated and are therefore set to the abovementioned temperatureranges. It is preferred to use at least two, preferably at least three,polishing rolls. The polishing rolls are set at different temperatures.According to a preferred embodiment, the lower polishing roll (when tworolls are used), or the middle polishing roll (when three or more rollsare present), which is the roll which comes into contact with thetwo-colored or multicolored plastic extrudate of the upper film, is setat a heat setting of more than 30° C., preferably more than 45° C.,hotter than that of the (upper) polishing roll which comes into contactwith the lower film(s). By means of the somewhat hotter setting of theone polishing roll, the colored extrudates of the upper film are notcooled suddenly and combine well with one another, without any loss ofthe colored contours. Cooling is effected by the roll on the lower film,and the diameter of this roll is kept smaller. The polishing roll onwhich the surface of the colored upper film (or colored extrudates forthe upper film) impinges and on which it lies therefore has a largerdiameter than the roll with which the lower film comes into contact.This polishing roll on which the upper film lies also offers the film alonger residence period. Thus, according to a preferred embodiment, thetemperature of the upper polishing roll (e.g., polishing roll 6) is from10° to 28° C., preferably from 18° to 24° C., the temperature of thepolishing roll below it (e.g., polishing roll 7) is from 60° to 85° C.,preferably from 75° to 82° C., and the temperature of the subsequentpolishing roll, (e.g. 7'), is from 15° to 35° C., preferably from 23° to33° C. According to a preferred embodiment, the temperature of the thirdand/or further subsequent polishing roll(s) (7' and, if appropriate,following rolls) is set at more than 25° C., preferably more than 35°C., below the temperature of the polishing roll, (i.e., the roll at theinlet) having the largest roll diameter. The temperature of the third(7') roll and/or of one or more subsequent rolls is preferably at leastequal to the temperature of the upper polishing rolls (6), but ispreferably more than 5° C. more than the temperature of the upper inletpolishing roll (6).

According to one embodiment, the film is subsequently provided with aprotective coating. According to still another embodiment, the film isprovided with a grain or embossed pattern.

The polymer films produced by the novel process are preferably subjectedto a thermoforming operation, given a foam backing and processed furtherto form dashboards.

According to another preferred embodiment, the polymer compositions ofthe lower film(s) and/or of the different-colored or two-colored upperfilm(s) which are to be extruded in accordance with the inventioninclude at least one crosslinking agent or crosslinking agent mixture,preferably a polymeric crosslinking agent or crosslinking agent mixturecomprising at least one polymeric crosslinking agent. The crosslinkingagent, preferably polymeric crosslinking agent, is preferably present inthe polymer composition or the extrudate of the lower film(s). Accordingto a preferred embodiment, in the latter embodiment the extrudate of thelower film(s) is, furthermore, arranged above the upper film containingtwo or more different-colored extrudate substreams, so that the two orthree extrudate substreams of the upper film, which have differentcolors or shades, are covered by the melt web or the extrudate web ofthe lower film(s). This produces a more rapid and/or better combinationof the film webs, with the contours being retained. In the case of theembodiment using crosslinking agents, preferably polymeric crosslinkingagents, these are added to the plastic mixture, preferably to the lowerfilm(s) together with a chemical compound which is crosslinkable orpartially crosslinkable, e.g. EPDM.

The polymer compositions of the upper and lower film preferably includeat least one polyolefin or a polyolefin mixture and/or a styrene graftor block polymer and also, in the case of the lower film, at least onepolymeric crosslinking agent as well.

According to a preferred embodiment, mass pressures of thedifferent-colored extrudate streams (measured on exit from the extruderor coextruder) are identical or virtually identical and differ by lessthan 60 bar, preferably less than 45 bar, from one another, although themass pressures of the different extrudate streams are higher than 250bar, preferably higher than 280 bar, and/or the mass temperatures of thedifferent-colored extrudate streams (measured on exit from the extruder)differ from one another by less than 30° C., preferably less than 15°C., with the mass temperature of the different-colored extrudate streams(measured on exit from the extruder) being set at more than 190° C.,preferably more than 210° C.

The mass pressure of the different-colored extrudate streams (measuredon exit from the extruder i.e., before the adapter or the black box) ispreferably from 300 to 450 bar, more preferably from 340 to 440 bar, andthe mass temperature (measured on exit from the extruder) is preferablyfrom 200° to 250° C., more preferably from 220° to 245° C.

According to a preferred embodiment at least one crosslinking agent,preferably a polymeric crosslinking agent, is used for the polymercomposition of the lower film(s) which is to be employed.

The polymeric crosslinking agent of the lower film or lower films, whichcontains reactive groups, in a preferred embodiment has not onlyacrylate and/or methacrylate groups and acrylic acid and/or methacrylicacid groups, and more than 51% by weight of ethylene and/or olefin or(CH₂) or CH groups, but also epoxide groups or epoxy-like groups,preferably glycidyl groups.

The polymers and/or ionomers of the lower film, which contain reactivegroups, preferably include as a metal ion alkali metal ions and/oralkaline earth metal ions and/or zinc ions.

According to one embodiment, the polymers and/or ionomers which possessreactive groups, contain alkyl acrylates and/or alkyl methacrylateshaving 1 to 8 carbon atoms.

The two different-colored melts are consequently laid onto a backingmelt by coextrusion, but are preferably covered by the melt of the lowerfilm. Owing to the fact that these two melts do not become mixed on theway to the die and in the die, because of their virtually identicalviscosity, and the fact that they are distributed uniformly over thewidth of the die, after having been separated beforehand in the adapteror in the black box, the distribution of the upper film or upper layerinto respective colored areas is achieved.

The invention additionally provides a device for the production oftwo-colored or multicolored switchboard films, dashboard films ordashboards produced therefrom, which comprises at least two extruders,at least one adapter or one black box, at least three openings and/orsupply connections for the supply of polymer melt from the respectiveextruder, and, downstream of the adapter, an extruder slot die (dieblock). In accordance with the invention, at least two of the openingsmade in the adapter are arranged on either side adjacent to awedge-shaped projection or projection of triangular cross section, andat least one further inlet opening or an inlet slit for at least onelower layer is disposed below the openings which are arranged on the twosides. In this arrangement, it is preferable to employ three or moreextruders.

According to a preferred embodiment, the tip of the wedge-shapedprojection or projection of triangular cross section which is arrangedabove the gaps or the opening for the melt of the lower film(s) or lowerlayer(s) is directed toward the gap or melt opening for the lower film.According to one embodiment, the tip is directed at the darker-coloredregion F, so that a relatively wide surface layer region A and arelatively small surface region F (dark-colored) is established in theemerging film. According to a further preferred embodiment, thewedge-shaped projection in the adapter or in the black box is configuredin the manner of a fillet or extended in the manner of a fillet. Thewedge-shaped projection is preferably arranged on an element, molding orinsert which can be inserted into or fastened in the adapter or in theblack box, preferably on a disk.

According to another preferred embodiment the wedge-shaped projection orprojection of triangular cross section forms, together with the gap orthe melt opening for the lower film, an angle of less than 90° (for onecolor region) and an angle of more than 90° and less than 160°,preferably less than 150° (for the other color region).

The invention additionally provides switchboard films, dashboard filmsor dashboards produced therefrom, comprising at least one backing layeror backing film, at least one upper film or upper layer which isarranged thereon and contains dyes and/or color pigments, and also, ifdesired, one or more additional layers or films. According to theinvention, the upper film or upper layer consists of at least two zonesor sections which extend parallel or approximately parallel, arerectangular or parallelogrammic in plan view and are pigmented orcolored differently, and the different-colored film(s) or upper layer(s)is or are produced as a composite film by coextrusion or multiextrusiontogether with at least one lower film or lower layer.

According to a preferred embodiment, the polymer composition for theupper and/or lower film comprises at least one propylene homopolymer,copolymer or graft polymer, propylene block copolymer or heterophasepropylene block copolymer and/or EPM or EPDM or a crosslinked orpartially crosslinked PP-EPDM, while the formulation of the lower filmincludes a polymeric crosslinking agent which has reactive groups, theformulations for the two-colored or multicolored upper films differingonly in the additives, preferably in the dyes and/or color pigments,and/or, if appropriate, fillers.

It has been found that, for the novel process for producing two-coloredor multicolored switchboard films, a highly suitable polymer formulationfor the lower film is one comprising (based on 100 parts by weight ofpolymer of the film) up to 60% by weight of at least one partiallycrosslinked EPDM, from 12 to 30% by weight of propylene homopolymer,copolymer or graft polymer with or without reactive groups, from 77 to9.5% by weight of at least one polymer and/or ionomer which containsreactive groups and is based on ethylene and methacrylic acid or acrylicacid, some of the acid groups containing metal ions or being neutralizedby metal ions, and from 10 to 0.5% by weight of at least one polymericcrosslinking agent which contains reactive groups and of which more than51% by weight (based on 100 parts by weight) comprises ethylene groupsor other olefin groups and from 1 to 49% by weight comprises acrylateand/or methacrylate groups and reactive groups, the reactive groupsbeing epoxide, isocyanate, ketone, aldehyde, silane, alkyl halide and/oranhydride groups, and also, if desired, at least one filler, additive,and/or processing auxiliary, or the polymer mixture consists thereof. Inthe context of the novel process, a particularly suitable compositionfor the two-colored or multicolored upper film is a polymer compositionwhich comprises (based on 100 parts by weight of polymer of the upperfilm) from 20 to 80 parts by weight of at least one crosslinked PP-EPDM(alloy or mixture of propylene homopolymer and/or copolymer andcrosslinked or partially crosslinked ethylene-propylene-diene copolymer)from 80 to 20 parts by weight of a noncrosslinked propylene blockcopolymer or heterophase propylene block polymer, having an elastomerfraction in the block or in the chain of from 35 to 75% by weight (basedon 100 parts by weight of the non-crosslinked heterophase propyleneblock copolymer or propylene block polymer), from 15 to 1% by weight,preferably from 10 to 20% by weight, is replaced by the same amounts byweight of an ionomer and/or polymer containing reactive groups, where atleast one ionomer and/or polymer which contains reactive groups and isbased on ethylene and methacrylic acid and/or acrylic acid is presentand some of the acid groups contain metal ions or are neutralized bymetal ions, the upper and lower film comprising, if desired, fillers,additives and/or processing auxiliaries.

In this context the composition of the upper film preferably includesone or more dynamically crosslinked or partially crosslinked PP-EPDM orPP-EPDM mixtures or alloys. The constituents of the upper film areemployed, if desired, in combination with processing auxiliaries,additives and/or fillers, but preferably with dyes and/or colorpigments.

According to a preferred embodiment of the upper film, the melt indexMFI (230/2.16) of the dynamically crosslinked or partially crosslinkedPP-EPDM mixture (determined in accordance with DIN 53735) is below 12g/10 min, preferably below 8 g/10 min, particularly preferably below 6g/10 min. According to a preferred embodiment, in this case one of theconstituents has a melt index MFI (230/2.16) of below 4.8 g/10 min,preferably below 2.5 g/10 min, particularly preferably below 1.8 g/10min, while the other constituent of the PP-EPDM mixture has a higherMFI.

With particular preference, for the upper film, the polypropylene, orthe homopolymer or copolymer fraction of the polypropylene, which is inthe PP-EPDM mixture or is present therein in dispersed form, has arelatively low melt index. According to a preferred embodiment, the PP(polypropylene) or the homopolymer or copolymer fraction (PP) present inthe mixture in dispersed form has a melt index MFI (230/2.16) of from0.1 to 2 g/10 min, preferably from 0.3 to 1.5 g/10 min (determinationmethod according to DIN 53735).

The polypropylene block of the noncrosslinked heterophase polypropyleneblock polymer preferably consists of a propylene homopolymer, copolymerand/or block polymer. The elastomer content of the heterophasepolypropylene block copolymer, according to a preferred embodiment, isfrom 40 to 70% by weight (based on 100 parts by weight of thenoncrosslinked heterophase propylene block copolymer). According toanother preferred embodiment, however, the elastomer content of theheterophase propylene block copolymer is from 35.5 to 48% by weight,preferably from 36 to 45% by weight (based on 100 parts by weight of thenoncrosslinked heterophase propylene block polymer).

According to a preferred embodiment, the elastomer of theethylene-propylene copolymer has an ethylene content of 20 to 70% byweight, preferably 30 to 60% by weight, and a propylene content of 80 to30% by weight, preferably 70 to 40% by weight, and has a molecularweight of more than 100,000, preferably more than 150,000.

The addition of a dynamically crosslinked PP-EPDM blend to the upperand/or lower film, with a particle size of the crosslinked elastomerphase of from 0.5 to 15 μm, improves the deformation range, theuniformity of thermal expansion and the grain pattern. An improved grainpattern means that the excessive expansion of the grain valleys as aresult of the increase in strength which accompanies increasingextension is limited (strain hardening). To most advantageously achievethis effect there should be homogenous incorporation of the crosslinkedPP-EPDM blend and a particulate elastomer structure. This gives rise tocertain requirements regarding the degree of crosslinking and the meltindex of the crosslinked PP-EPDM blend used. The degree of crosslinkingin the complex systems, defined indirectly via the compression set at70° C. after 22 h (DIN 53517), should be between 25 and 60.

The heterophase propylene block polymer used is preferably a blockpolymer having an MFI 230/2.16 (g/10 min) of 0.3 to 8, preferably from0.5 to 7.

The PP-EPDM, preferably dynamically crosslinked or partially crosslinkedPP-EPDM, used for the upper and/or lower film(s) is preferably that witha density of between 0.78 and 0.96 g/cm³, preferably from 0.83 to 0.93g/cm³. The PP-EPDM selected for this purpose preferably has an initialflexural modulus--measured in accordance with ASTM D 790 with a 2 mmfilm web--of from 80 to 400 MPa, preferably from 100 to 300 MPa.

According to a preferred embodiment the lower film or lower films (basedon 100 parts by weight of polymer of the lower film or lower films)comprises from 5 to 55% by weight of at least one partially crosslinkedEPDM, from 13 to 25% by weight of propylene homopolymer, copolymer orgraft polymer with or without reactive groups, from 73 to 19% by weightof at least one ionomer and/or polymer which contains reactive groupsand is based on ethylene and methacrylic acid or acrylic acid, some ofthe acid groups containing metal ions or being neutralized by metalions, and from 9 to 1% by weight of at least one polymeric crosslinkingagent which contains reactive groups and more than 51% by weight (basedon 100 parts by weight) of ethylene groups or other olefin groups andfrom 1 to 49% by weight of acrylate and/or methacrylate groups andreactive groups, the reactive groups being, epoxide, isocyanate, ketone,aldehyde, silane, alkyl halide and/or anhydride groups, or the lowerfilm(s) contain(s) these constituents.

The novel thermoformable composite films possess a degree of gloss inaccordance with DIN 57530/600 of from 0.5 to 5 of the upper film, whichis substantially influenced neither by the necessary deformationtemperature nor by the thermoforming ratio. This feature, therefore,distinguishes the novel films from the knowledge gained from previousexperience with films which have been rendered matt by means of fillersor embossing.

Using the novel additive and/or the novel mixture for the production ofthermoformable automotive films it is possible to obtain polymer filmswith a matt surface and with high elasticity for the thermoformingoperation. In this context, the thermoforming of the novel compositefilm can be carried out within a broad temperature range from about 140°to 200° C., preferably from 150° to 185° C., without any particularproblems. The film has excellent thermoforming properties and can beemployed either in positive thermoforming or in negative thermoforming.Using the composition it is possible to obtain thermoformed films havinga Shore D hardness from 25 to 60, preferably from 30 to 55, and aGardner gloss at 60° of from 0.5 to 1.5, measured on the thermoformedarticle.

The novel automotive composite film webs for interior trim have theadvantage, moreover, of high ageing stability with respect to light andheat, and also low fog values.

According to a preferred embodiment, the upper film and/or lower filmhas a filler content of 0 to 30 parts by weight, preferably from 0 to 20parts by weight (based on 100 parts by weight polymer). Fillers whichcan be employed are the fillers known per se, preferably talc and/orSiO₂ having a mean particle size of from 0.01 to 20 μm preferably from0.05 to 10 μm.

Processing auxiliaries employed include, preferably, heat stabilizersand/or light stabilizers for polyolefins.

Further processing auxiliaries or additives used include lubricants ormixtures of lubricants.

According to one embodiment, an adhesion promoter layer is preferablyarranged below the film layer. The adhesion promoter layer preferablycomprises or consists of acrylates, polyurethane or acrylatepolyurethane mixtures. Below the film layer or adhesion promoter layerthere is preferably a foam layer, a backing layer, a fabric layer and/ora support layer. The foam layer preferably comprises or consists of apolyolefin foam or polyurethane foam.

The upper film preferably has a mean thickness of from 60 to 500 μm,more preferably from 100 to 350 μm. The lower film or lower filmspossess an average thickness of from 100 to 2000 μm, preferably from 500to 1500 μm, and have an overall thickness which is more than 1.5 times,preferably two or more times, that of the upper film.

The novel composite film can be thermoformed very readily and is used toproduce low-strain articles with precise reproduction of dimensionallyor temperature-stable surface structural features. The composite film ispreferably machined or processed in the positive thermoforming processand/or negative thermoforming process. On the bottom side or bottomsurface the composite material preferably has a foam layer, for example,polyurethane foam, but preferably polyolefin foam, and/or is providedwith a backing layer or a backing and/or a support layer and/or alattice or fabric layer. The film or layer is provided in accordancewith a preferred embodiment with decorative features, grains, embossedpatterns and the like, has a stable grain, is pleasant to touch and canbe printed. Using the novel composite film it is possible to produceshaped components or articles whose surface has good grain stabilityeven on storage under hot conditions.

In this context, according to a preferred embodiment, the backing layerand/or foam layer contains polyolefins or is based on polyolefins.

The polymeric crosslinking agent of the lower film or lower films, whichcontains reactive groups, in a preferred embodiment has not onlyacrylate and/or methacrylate groups and acrylic and/or methacrylic acidgroups, and more than 51% by weight of ethylene and/or olefin or (CH₂)or CH groups, but also epoxide groups or epoxy-like groups, preferablyglycidyl groups.

The reactive-group-containing polymers and/or ionomers of the lower filmpreferably include, as the metal ion, alkali metal ions and/or alkalineearth metal ions and/or zinc ions.

According to one embodiment, the ionomers and/or polymers which possessreactive groups contain alkyl acrylates and/or alkyl methacrylateshaving 1 to 8 carbon atoms.

According to a preferred embodiment of the invention the upper film hasor is adjusted to a Shore D hardness which is less by more than 3 ShoreD units, preferably from 5 to 10 Shore D units, than the Shore Dhardness of the lower film(s), and/or the surface tension of the upperfilm is adjusted to a value of more than 40 mN/m.

By appropriately selecting the weight of the constituents of the upperfilm, and preferably of the constituents within the stated amounts byweight of the constituent, the Shore D hardness of the upper film ispreferably adjusted to a Shore D hardness of less than 37, morepreferably to a Shore D hardness of from 28 to 35, and/or, byappropriately selecting the weight of the constituents of the lowerfilm(s), preferably of the constituents within the stated amounts byweight, the Shore D hardness of the lower film(s) is preferably adjustedto at least 38 Shore D, more preferably from 39 to 48 Shore D.

According to another preferred embodiment, at least one polyacrylate-,polymethacrylate- and/or polyurethane-containing layer is arranged abovethe upper film or on the film surface and/or below the lower film, thethickness of said layer being less than that of the upper film or lowerfilm, and in this context the layer thickness of the coating preferablybeing less than 50% of the layer thickness of the upper and lowerfilm(s).

In this arrangement, the upper film, and, if desired, areas of the lowerfilm(s) are preferably embossed or grained and the surface is providedwith a polyacrylate-, polymethacrylate- and/or polyurethane-containinglayer or coating which includes from 0.01 to 18% by weight, preferablyfrom 0.1 to 12% by weight, of at least one finely divided matting agentand is coated by applying a diluent.

According to a further embodiment, the polymer composition of the lowerfilm includes, as synthetic resin, from 65% by weight to 90% by weight(based on 100% by weight plastics fraction of the lower film) ofpropylene homopolymer, copolymer, terpolymer and/or block polymer andfrom 35 to 10% by weight of ethylene-vinylacetate copolymer having avinyl acetate content of from 10 to 40% by weight, and also, if desired,from 0.1 to 5.0% by weight of a crosslinking agent, preferably apolymeric crosslinking agent, or of at least one peroxide or compoundcontaining peroxide groups.

According to another embodiment, the polymer composition of the lowerfilm includes at least one partially crosslinked EPDM, a propylenehomopolymer, copolymer or graft polymer, with or without reactivegroups, and also, if desired, an ionomer or polymer containing reactivegroups or a styrene- or polystyrene-containing block, diblock ortriblock and/or graft polymer which is replaced in whole or in part by amodifying agent based on a propylene-maleic anhydride copolymer or graftpolymer, a propylene-acrylic acid copolymer or graft polymer, anethylene-vinylacetate copolymer, an ethylene-acrylic acid or methacrylicacid copolymer, an ethylene-acrylic acid copolymer, an ethylene-acrylatecopolymer, a glycidyl methacrylate co- and/or terpolymer, preferably anolefinic or olefin group- containing glycidyl methacrylate co- and/orterpolymer, an ethylene-glycidyl methacrylate terpolymer, an olefinicionomer, a polyurethane, a polycaprolactone, a polyester ether and/or apolyetheramide.

The constituents of the lower film are preferably selected such that thelower film produced therefrom (based on the initial or final crosssection of the lower film) has a maximum stress-strain in the range from30×10² to 150×10² (these values being determined at a constantdeformation rate at 170° C.) and/or such that the stress-strain curve,after reaching the maximum, runs approximately parallel to the extensionaxis in the case of extension of more than 150%, preferably more than300% extension, and/or there are only small differences in viscosity ofthe two-colored or multicolored upper film at the respective processingtemperatures.

According to another embodiment, the formulation of the two-colored ormulticolored upper film comprises or consists of, as polymer componentor polymer mixture, (x) from 5 to 80 parts by weight of at least oneelastic polymer which contains reactive groups or of at least onethermoplastic elastomer which contains reactive groups or a polymer orpolymer mixture which contains reactive groups and has a portion ofelastic polymer of more than 60% by weight (based on 100 parts by weightof the elastomer-containing polymer or polymer mixture), and (y) from 95to 20 parts by weight of at least one olefin copolymer, terpolymerand/or graft polymer which contains reactive groups and/or of an ionomerwhich contains or is based on a polyolefin homopolymer, copolymer,terpolymer and/or graft polymer, the modulus of elasticity of themixture of (x) and (y) or the modulus of elasticity of the thermoformedpolymer film or polymer film web produced therefrom or of the layerbeing preferably from 30 to 1000 N/mm², more preferably between 50 and600 N/mm², the reactive groups being carboxyl, hydroxyl, anhydride,amine, amide, isocyanate, epoxy and/or nitro groups, and/or theviscosity being established such that there are only small differencesin viscosity at the respective processing temperature relative to thelower film.

According to one embodiment, the proportion by weight is from 0.2 to 30%by weight, preferably from 0.3 to 25% by weight, based on, the elasticpolymer(s) containing reactive groups (calculated at 100 parts byweight) or thermoplastic elastomer(s) or polymer mixture(s) containingreactive groups in accordance with (x), and from 0.2 to 25% by weight,preferably from 0.5 to 20% by weight, based on the polyolefin(s)containing reactive groups or polyolefin-containing ionomer(s)(according to (y)).

The drawings show, in diagram form, embodiments of the novel processusing the novel apparatus.

In FIG. 1 the extruder (1) is combined with or provided with coextrusiondevices (2) and (3), the black box (4) and the slot die (5).

In the simple embodiment according to FIG. 1, the multilayer compositefilm passes to the polishing rolls (6) and (7) (with or withoutembossing structure) and to the other polishing roll (7').

According to the preferred embodiment in FIG. 1, the wedge-shapedprojection (8) or projection (8) of triangular cross section is shown indiagram form in the adapter or black box. The projection (8) is arrangedon the insert (9).

FIG. 2 represents a plan view of the insert which is to be inserted inor fastened to the adapter or the black box. In FIG. 2, two of thecircular openings 12 made in the adapter are arranged on either side ofand adjacent to a wedge-shaped projection or projection of triangularcross section 8, and at least one further entry opening or an entry slot14 is made for at least one lower layer below the opening which isdisposed on both sides.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification beconsidered as exemplary only, with the true scope and spirit of theinvention being indicated by the following claims.

What is claimed is:
 1. An apparatus for the production of two-colored ormulticolored films, suitable for producing dashboards comprising:atleast two extruders; at least one adapter having at least three openingsat least two of which are for receiving a supply of polymer melt from arespective extruder; and downstream of the adapter, an extruder slotdie, wherein at least two of the openings made in the adapter arearranged on either side adjacent to a projection of triangular crosssection, and at least one further opening is an inlet opening for atleast one backing layer and is disposed on the opposite side of theprojection from the openings which are arranged on the two sides of theprojection.
 2. The device as claimed in claim 1, wherein a tip of theprojection of triangular cross section is directed toward the inletopening for the backing layer.
 3. The apparatus as claimed in claim 1,wherein the projection is arranged on an insert which can be insertedinto the adapter, where the respective insert and the projectioncomprise a rigid material that does not deform under the influence ofpolymer mass streams.
 4. The apparatus as claimed in claim 1, whereinthe projection of triangular cross section forms, together with theopening for the backing layer, an angle of less than 90° for one colorregion, and an angle of more than 90° and less than 160° for the othercolor region.
 5. The apparatus as claimed in claims 1, furthercomprising a polishing-roll stack having at least two rolls positioneddownstream of the extruder slot die.
 6. An apparatus for the productionof two-colored or multicolored films, suitable for producing dashboardscomprising:at least two extruders; at least one adapter having at leastthree openings at least two of which are for receiving a supply ofpolymer melt from a respective extruder; and downstream of the adapter,an extruder slot die, wherein at least two of the openings made in theadapter are arranged on either side adjacent to a projection oftriangular cross section, and at least one further opening is an inletopening for at least one backing layer and is disposed on the oppositeside of the projection from the openings which are arranged on the twosides of the projection, wherein a tip of said projection of triangularcross section is directed toward the inlet opening for the backinglayer.